MGA Spine

Osteoporosis and Osteoarthritis

Normal changes with age, compression of body Osteophytes usually develop at joints Usually in lumbar

A 50-year-old male presents for a wellness visit with neck pain. Imaging confirms a fracture of the C2 spinous process. The function of which muscle is most likely to be affected?

Obliquus capitis inferior

One cervical vertebra has a structure that none of the other vertebrae have. This single structure is designed to permit rotation of the head. This structure is called the __________ and is found only on vertebra number __________.

One cervical vertebra has a structure that none of the other vertebrae have. This single structure is designed to permit rotation of the head. This structure is called the __________ and is found only on vertebra number __________. Dens, C2

One vertebra participates in 2 facet joints on each side Meaning the superior articular facet of T4 contacts inferior articular facet of __, and the inferior articular facet of T4 contacts the superior articular facet of __

One vertebra participates in 2 facet joints on each side Meaning the superior articular facet of T4 contacts inferior articular facet of T3, and the inferior articular facet of T4 contacts the superior articular facet of T5

Transverse Foramina

Only part of cervical vertebrae Vertebral artery (branch of subclavian artery) Gets Blood to brain

Compression Fractures are often caused by:

Osteoporosis causes compression fractures, which can lead to excessive thoracic kyphosis ●Lower thoracic spine is most common site of osteoporotic compression fractures

Bifid Spinous Process

Part of cervical vertebrae C2-C6

Difficulty standing upright after touching his toes. What is the innervation of the muscle (s) that are most likely dysfunctional

Posterior rami of spinal nerves (bending forward = flexion)

Vertebral Column Curvatures

Primary Curvatures •Thoracic and sacral kyphoses •Anterior concavity •Present in fetus Secondary Curvatures •Cervical and lumbar lordoses (top of the rainbow towards the belly button) •Posterior (Cave is looking back beind) concavity •Prominent around first year: infant raises head, starts to walk Functions •Flexibility and shock absorption

Movements of the scapula

Prime movers in bold

Rebound Hyperflexion

Rebound hyperflexion can cause severe hyperflexion. May cause facet jumping of cervical vertebrae Can severely stretch/tear the PLL and interspinous ligament

What are the meninges innervated by?

Recurrent meningeal branches

Which muscle would be effected by a dorsal scapular nerve injury?

Rhomboid Major/minor Levator Scapulae

Inferior Lumbar Triangle (of Petit)

Roof : Skin borders: Inferior: iliac crest Lateral: Ext ab oblique Medial: lat dorsi Floor: int ab oblique Commn location for herniation of abdominal contents

Triangle of Auscultation

Roof: skin Borders: Lateral: medial border scapula Medial: Trapezius Inferior: Lat dorsi Floor: erector spine

Special Vertabrae: Sacrum and Coccyx

Sacrum •5 fused elements, triangular-shaped •Transmits weight to pelvic girdle • Coccyx •4 fused elements (actually 3-5) •Non-weight bearing

Nervous system functional divisions

Sensory and motor are two main division of functional NS

Intermediate (Extrinsic) Muscles *Outside of back proper

Serratus posterior superior: Action: Elevates ribs, Proprioception Innervation: Intercostal nn Serratus posterior inferior: Action: Depresses ribs, Proprioception Innervation: Intercostal nn *paper thin muscles, often adhere to layers of fascia prox: C7-T3, T11-L2 dist: ribs 2-4, 8-12 n: intercostal nn., anterior (ventral) rami spinal nn. a: proprioception (elevate, depress ribs) Serrated like a steak knife where it attaches to ribs (at the back and top and back and bottom:

Arch of Vertebrae

surrounds spinal cord, forms vertebral foramen Made up of: •Laminae •Pedicles (feet) -Superior + inferior vertebral notch = intervertebral foramina (the hole where the Spinal nn. (nerves) exit canal) (not the hole in the middle, thats the vertebral column) *Shown in pink

Levator Scapulae (Superficial/Extrinsic Muscle)

prox: C1-C4 dist: medial border scapula (Innervation/nerve) n: dorsal scapular n. (a.): elevate scapula, rotate GH joint Blood Supply (rhomboids too): Dorsal Scapular Artery (Deep Branch of Transverse Cervical Artery)

Rhomboid Major and Minor (Superficial/Extrinsic Muscle)

prox: C7-T5 dist: medial border scapula n: dorsal scapular n. a: retract and adducts scapula, rotate GH joint MINOR OVER MAJOR

Trapezius Superficial (Extrinsic) Muscles

prox: EOP, nuchal lig, C7-T12 dist: clavicle, acromion and spine scapula n: spinal accessory n. (CN XI) a: elevate, depress, retract scapula

Latissimus Dorsi (Thiq Boy)

prox: T7-12, thoracolumbar fascia dist: intertubercular sulcus humerus n: thoracodorsal n. a: extend, adduct, medially rotate humerus *broadest muscle of the back, chin-up muscle

Suboccipital Triangle

•3D, pyramidal-shaped space •Inferior to external occipital protuberance, deep to sup part of post cervical region *four important muscles in this region Just posterior to spinal cord, buried very deep Roof: First, Trapezius,then splenius capitis (cut and reflect that too), refelect semispinalis capitis (this is the roof) Boundaries: Rectus capitis Posterior major, obliquis capitis superior, obliquus capitis inferior * Obliquis capitis inferior (not a boundary but still there) Contents: Vertebral Artery, Suboccipital nerve (branch of C1, splits to innervate four occipital muscles) Floor: Posterior atlanto-occipital membrane Landmarks: Look for spinous process for C2, look for transverse process of C1 Greater occipital nerve runs near the triangle (but outside of the traingle): emerges off of C2, below obliquuus capitis inferior, then makes its way up and out -Let C2 guide you to the inferior border *release area, regain function, alleviate pain To review: Roof: Semispinalis capitis SuperoMedial Boundary: Rectus capitis posterior major SuperoLateral (upper side) Boundary: Obliquus capitis superior InferoLateral Boundary: Obliquus capitis inferior Contents: Vertebral a., suboccipital n. (C1) Floor: Post atlanto-occipital membrane, post arch C1

Blood Supply of Spinal Cord

•Branches from vertebral, ascending cervical, deep cervical, intercostal, lumbar, and lateral sacral aa. -Anterior and posterior segmental medullary aa. • •3 longitudinal aa.: anterior spinal a., paired posterior spinal aa. -Branches off vertebral aa. •

anterior longitudinal ligament

•Broad, strong •Covers anterior body to intervertebral foramina, extends from occipital bone to sacrum •Resists hyperextension!!!!(because its in front of vertebral column)

cauda equina

•Bundle of fibers below conus medullaris (termination of spinal cord) (termination aroun L1-L2)

Regions of Vertebrae

•Cervical = C 1-7 (7) •Thoracic = T 1-12 (12) •Lumbar = L 1-5 (5) •Sacral = S 1-5 (5) Coccygeal = Co 1-4 (4) Sacral and coccygeal are FUSED (less mobile) Should add up to 33 vertebrae! (12 pairs of ribs) -Some variation between bodies imagine a cereal breakfast at 7 am (7 cervical vertebrae), a tasty lunch at 12 noon (12 thoracic vertebrae), and a light dinner at 5 pm (5 lumbar vertebrae), Sweet dessert (Sacral)

Spina Bifida

•Developmental anomaly, malformation of vertebral arch

Venous Drainage of Spinal Cord

•Distribution like aa. •3 anterior and 3 posterior spinal vv. •Drain into internal vertebral venous plexus to dural sinuses and intervertebral vv.

Accessory Ligaments of Intervertebral Joints: Nuchal Ligament

•Fibroelastic tissue, thick band •Extends from occipital protuberance to cervical spinous process •Provides m. attachment and supports head *Behind vertebral body, helps resist hyperflexion (Behind vertebrae limits flexion, in front of vertebrae limits extension!)

Deep (Intrinsic) Muscles (Superficial, intermediate, and deep levels within this)

•Innervated by posterior (dorsal) rami of spinal nn. •Involved in posture and moving vertebral column Segmental: arising and inserting on many levels •Smallest muscles act primarily as proprioceptors Superficial Layer: Spinotransversales Splenius cervicis Splenius capitis Intermediate Layer: Erector Spinae Group Iliocostalis Longissimus Spinalis Deep Layer: Transversospinalis: -Semispinalis -Multifidus -Rotatores Interspinales Intertransversarii Levatores costarum Minor group Stabilization, extension, rotation, lateral flexion *Mneumonic :Some cats steal catnip, easy snack: I love snacks too: since my ragamuffin is innocent little cat. / so many intelligent individuals love cats

Vasculature of Vertebral Column (Veins (Vv.))

•Internal and external vertebral venous plexuses (loarge rat nest inside vertebal plexus and outside) •Drain into intervertebral vv.

Ligamentum Flavum

•Joins adjacent laminae •Resists abrupt flexion and separation of laminae

Spinal Meninges

•Layers of connective tissue and spaces that surround, support, and protect the spinal cord and spinal nn. •Subarachnoid: Contains cerebrospinal fluid (CSF) Drura, Arachnoid, pia: D.A.P (from superficial to deep) Outside of the dura is the epidural space Dura-arachnoid interface/subdural space could potentially be filled during a trauma

Spinal Cord Where does the spinal cord terminate?

•Major reflex center and conduction pathway between body and brain • •Protected by vertebrae, meninges, and CSF •from foramen magnum, spinal cord is Continuation of medulla oblongata in brainstem down to ***L1-L2***: Terminates at conus medullaris Bundle of fibers below termination= cauda equina (horsestail): this is how we get nerves down the rest of the vertebral canal Embryonic origins Cord and column begin at same length Column grows faster along with body Cervical (C4-T1) and lumbosacral (T11-S1) enlargements (expanision of diameter becuase there are more parts going in and out) •Nerve fibers entering and leaving cord from UL and LL •Brachial and lumbosacral plexuses innervate UL and LL

posterior longitudinal ligament

•Narrow, weak •Attaches to IV discs •Resists some hyperflexion

Recurrent meningeal branches of spinal nn. (nerve)

•Nociception, proprioception, and sympathetics (vasoconstriction) *Goes back to where it came from, then branches off and distributes to meninges, other important stuff

Craniovertebral Joints : Atlanto-occipital (locate the major craniovertebral joints)

•Occipital condyles and sup facets C1 •Flexion and extension (some lateral flexion and tilting)

Hyoid Bone

"Free floating:" Does not articulate with any other bone Can be fractured or damaged during strangulation Betwen mandible and larynx

Vertebral Ligaments

"Intervertebral discs generally herniate posterolaterally, due to the thin posterior longitudinal ligament along the midline of the vertebral bodies." First Aid USMLE -Everything posterior to ALL limits flexion -Supraspinous ligament - Connects tips of spinous processes -Ligamentum flavum - attach to laminae, resists abrupt flexion and separation of laminae -Interspinous ligament - Between adjacent spinous processes, limits flexion -PLL - attaches to IV discs, narrow, weak -ALL - broad, strong, can be torn/stretched by whiplash Nuchal ligament - Fibroelastic tissue, thick band, extends from occipital protuberance to cervical spinous process, provides m. attachment and supports head

Proximal, distal, origin, insertion, extrinsic, intrinsic

*Proximal - toward or nearest the trunk (example, the proximal end of the femur joins with the pelvic bone). Distal - away from or farthest from the trunk or the point or origin of a part (example, the hand is located at the distal end of the forearm) Origin= Fixed attachment (Not moving) Insertion: Other part that gets pulled towards the origin Extrinsic: proximal and distal attachemnts are in different parts of the body: Trapezius Intrinsic muscles: proximal and distal attachmetns within same body region (among adjacent vertabrae)

Movements at Intervertebral Joints: Cervical

1. Semispinalis cervicis, Iliocostalis cervicis 2. Splenius cervicis, Levator scapulae 3. Splenius capitis 4. Multifidus 5. Longissimus (capitis) 6. Semispinalis capitis T. Trapezius

Thoracic Vertebrae

12 Costal facets/demifacets Longer transverse processes Little divots where you have articulation with the ribs = Less mobile than cervical and lumbar

A 40-year-old male presents in the emergency department following a motor vehicle accident. Considering the image, which muscle is most likely to be affected?

A 40-year-old male presents in the emergency department following a motor vehicle accident. Considering the image, which muscle is most likely to be affected?

Posterior and Anterior Ramus

After we cross the dotted line in the image, we have mixed motor and sensory: Spinal nerve exiting through intervertberal foramen -Then the fibers split Posterior ramus: fibers that take care of deep back muscles and overlying skin, synovial joints of vertebral column anterior ramus: skin and hypaxial mm. of anterior and lateral regions, plus limbs: head to the rest of the body

Nerve Roots and Spinal Nerves Anterior (ventral) = Posterior (dorsal) =

Anterior (ventral) = Motor (efferent) Posterior (dorsal) = Sensory (afferent) *Rearrange for acronym S.A.D (sensory, afferent, dorsal) Gray matter looks like a butterfly in the middle: Made up of neuron cell bodies (nuclei are here) White matter surrounds it, made of myelin sheath that surround axons

A 45 year old male presents to ER after MVA. Reports being struck from behind, complains of deep neck pain when he looks up. Which supporting structure is likely damaged?

Anterior Longitudinal Ligament

What is the innervatin of extrinisic muscles of the back

Anterior rami of spinal nerves

At which vertebral level does the T12 spinal nerve exit? A herniated IV disc at which vertebral level would affect the T12 spinal nerve

At which vertebral level does the T12 spinal nerve exit? Between T12 and L1 A herniated IV disc at which vertebral level would affect the T12 spinal nerve? Between T11-T12

What joint allows for the No-No movement?

Atlanto-Axial Joint

Craniovertebral Joints : Atlanto-Axial (locate the major craniovertebral joints)

Atlanto-axial •1. Median atlanto-axial: ant arch1 C and dens C2 •2. L and 3. R lateral atlanto-axial: inf facets of C1 and sup facets C2 •Rotate head side to side

Regional Characteristics of Presacral Vertebrae: (describe shape of): Cervical Thoracic Lumbar

Bodies get larger as you descend column Cervical: small body, convex/concave surface bifid spinous process transverse foramina within the lateral aspects (vertebral artery passes through here) (C1-C6) Thoracic: (Image shown) -heart-shaped body -long spinous process (points downward) -costal demifacets (articulate with the ribs) -transverse costal facets (only on thoracic) Lumbar: Large, kidney shaped body

The obliquus capitis superior and inferior muscles have attachment points on the transverse process of this vertebra:

C1

Transection of Spinal Cord (not tested)

C1-C3: no function below head, ventilator needed C4-5: quadriplegia, respiration occurs C6-C8: loss of LL function, variable UL function T1-T9: paraplegia, variable trunk control T10-L1: some thigh muscle function, walking with braces L2-L3: retention of most leg function, short braces needed *Schematic diagram demonstrating the appearance of cord transection on T1W and T2W images. A young woman sustained a lap-belt flexion distraction injury during a head-on motor vehicle accident. T1W (b) and T2W (c) images demonstrate tears of the flaval ligaments (black arrowhead) and posterior dura (open black arrow). There is a partial rent at the same level in the cord (open white arrow). The cavity is filled with cerebrospinal fluid confirmed on both T1W and T2W images.

Special Cervical Vertebrae

C1: atlas, has transverse ligament -Articulates head -Lacks spinous process and vertebral body -Nod head yes -Atlas (C1) articulates with the occipital condyles -Allow flexion and extension of head on C1 (Yes -Yes joint) C2: axis, odontoid process (AKA Dens): little knob that sticks up (articulates with the anterior arch of atlas) -Shake head no -1.HAS BIFID SPINOUS PROCESS 2.HAS A BODY (its kind of underneath) C7: vertebra prominens _usually most posteror/prominent spiny process

Where does the vertebral artery enter the transverse foramina to travel superior to the head?

C6

Central NS and Peripheral NS

Central Nervous System •Brain •Spinal cord •Nuclei = neuron cell bodies Peripheral Nervous System •Ganglia = neuron cell bodies •Cranial nn. •Spinal nn., plexuses, named nn.

Examples: Cervical extension muscle Example: Cervical Lateral flexion muscle: Cervical rotation muscle example: Thoracic and lumbar extension muscle: T&L lateral flexion: T&L rotation muscles:

Cervical extension muscle Example: splenius capitis Cervical Lateral flexion muscle: Splenius cervicis Cervical rotation muscle example: Multifidus , semispinalis Thoracic and lumbar extension muscle: Rotatores T&L lateral flexion: Iliocostalis T&L rotation muscles: Logissumus

Trapezius Muscle innervated by what nerve?

Cranial nerve XI innervates the motor function of the trapezius. The function of the trapezius is to stabilize and move the scapula -Descending/Superior/Upper: Elevate Scapula, "Shrug Shoulders" -Middle/Transverse: ADduct/Retract Scapula -Ascending/Inferior/Lower: Depress scapula from an elevated position -Descending + Ascending: upwardly rotates the scapula Origin: External occipital protuberance, SP C7-T12 Insertion: Clavicle, acromion, and spine of scapula Action: Elevate, depress, retract, scapula Innervation: Spinal accessory nerve (cranial nerve 11 (XI))

What is the unilateral action of the splenius cervicis muscle?

D. Rotation of the head/neck to the ipsilateral side

Odontoid Process

Name for specific part of C2.

The part of a spinal nerve that supplies the deep back muscles and the skin overlying them is the:

Dorsal primary ramus

Three Maters

Dura Mater Tough Mother: Exterior most meninge/ covering of the central Nervous system -Superficial, fibrous tissue Separated from vertebral periosteum by epidural space Filled with adipose and internal vertebral venous plexus Potential space Spinal dural sac Long tubular sheath form foramen magnum to coccyx Continuous with cranial dura Sitting right up against it is the arachnoid mater (spiderlike mother) -Intermediate, delicate, fibroelastic tissue -Encloses Subarachnoid space, where CSF exists CSF bathes CNS with fluid, helps cushion and presevre it, helsp more waste away -Lumbar cistern: enlargement of space L2-S2, contains cauda equina Connected to dura via dura-arachnoid interface Pathologically created subdural space: subdural hematoma Arachnoid trabeculae connect to pia mater Spinal Pia Mater (tender mother) Deep, thin, and transparent membrane Follows surface of spinal cord Filum terminale anchors spinal cord Extensions of Pia Mater: Denticulate ligaments extend laterally: Help seperate dorsal and ventral root (little teeth that help anchor the cord) D.A.P

Deep (Intrinsic) Back: Intermediate Layer Erector Spinae Group: ILS

Erector Spinae Group Iliocostalis Longissimus Spinalis (closest to spine medially) •important for posture: Primary extensors of vertebral column •Lateral flexion *Make spine erect/extend back Going from lateral to medial in location: I (most laterally, farthest from spine) Love Spaghetti

Anteriorly concave cervical and thoracic spine: Likely diagnosis

Excessive Kyphosis

Abnormal Curvatures

Excessive kyphosis: hump/hunchback •osteoporosis, trauma -AKA Dowager's hump Excessive lordosis: sway/hollowback •excess anterior weight -Lordosis: Lumbar, cervicaL (lots of L's) -Pregnancy Scoliosis: Excessive lateral curvature •Functional: neuromuscular imbalance (something wrong with firing of nerves in spinal muscles) •Structural: hemivertebra, trauma -Structural vs idiopathic

The function of the suboccipital muscles is to:

Extend the head and rotate it toward the same side Made up of two oblique and two rectus muscles (rectus capitus major and minor, two of each)

Boundaries: Posterior aspect of the trunk Extends from the ________ ______ of the _____ to the ________ ________ of the _________

Extends from the inferior portion of neck to superior aspect of buttocks/ gluteal cleft

Movements of the vertebral column (Vertebrae+ Connective tissue)

Extension (lean back) Flexion (bend forward) Lateral flexion (lean to side) Lateral extension (lean back to center) Rotation

Filum Terminale

Extension of the PIA MATER Pierces dura to anchor end of inferior spinal cord Two parts: Filum terminale internum and exeternum Externum: dural portion anchoring to coccyx (coccygeal ligament)

Movements at Intervertebral Joints: Thoracic and Lumbar

Focus on names we have discussed, don't really worry about in parenthesis

Spinal Stenosis *Stenosis means narrowing of a tube

Narrowing of vertebral canal, compression of cord and spinal nerves Most common in lumbar region

Processes of Vertebrae (There are three, be able to say how many of each there are)

Function: Muscle and Ligament attachment Remember: STA Spinous process (1), Transverse process (2: one on each side of arch), (superior and inferior) articular processes (zygapophyses) (4 total)

Body of Vertebrae

Function: Weight Bearing

Notches (superior and inferior)

Indentations on pedicles Two notches come come together to form intervertebral foramen Important for passage of spinal nerves

Accessory Ligaments of Intervertebral Joints: Interspinous and supraspinous ligaments

Interspinous (thin, membranous) and supraspinous (thick, fibrous) ligaments •Connect adjacent spinous processes •Limit flexion

At birth, the entire spine is:

Kyphotic (C-shaped) Cervical lordosis develops at 3 months - when they start lifting their head up Lumbar lordosis develops at 10-18 months - when they start to walk Lordosis = posterior concavity (C curve facing outward), kyphosis = anterior concavity (C curve (top of the rainbow) facing outward: think of a bow and arrow: the curve is your bow. Anterior, the arrow is shooting out the back) *Lordosis: like a big fat Lord with his belly making him have that sway back

The conus medullaris marks the tapered end of the spinal cord. It is a landmark that ends around these vertebral levels:

L1-L2

Posterior View of Herniated disk with arch removed (standing behind patient)

L4 spinal nerve wont be compressed, but nerve below will be effected by herniated disk

Extrinsic (Superficial) Back Muscles (there are four) (there are also intermediate extrinsic muscles on later slide)

LS, T, RMAM, LD Mneumonic: Loving strippers trade riches, money, and men, living dirty. Levator Scapulae Trapezius Rhomboid Major and minor Latissimus Dorsi •Innervated by anterior (ventral) rami of spinal nn. (nerves) •Move upper limbs -Proximal attachment on vertebral column and ribs -Distal attachment on pectoral girdle and humerus (somewhere in the upper limb)

Lateral Horn

Lateral horn: T1 to L2 about level two (only in thorasic and upper lumbar levels (sympathetic function) DRG = posterior root ganglion: collection of sensory nerves outside of CNS

Ligaments of Intervertebral Joints: L P A

Ligamentum flavum •Joins adjacent laminae •Resists abrupt flexion and separation of laminae • Posterior longitudinal ligament •Narrow, weak •Attaches to IV discs •Behind the column, Resists some hyperflexion Anterior longitudinal ligament •Broad, strong *In front of column •Covers anterior body to intervertebral foramina, extends from occipital bone to sacrum •Resists hyperextension!!!(backbend) Anterior image of vertebral column with no body

Lumbar Puncture vs Epidural

Spinal/Lumbar Puncture ●Needle is placed in subarachnoid space (lumbar cistern) which contains CSF ●PIERCES DURA & ARACHNOID MATERS Epidural ●Catheter placed in epidural space ●NONE OF THE MENINGES ARE PIERCED

Vertebra Prominens

Spinous process of C7 Its the part that sticks out extra far if you tuck your chin to your chest (feel the bony part just below your neck) Its the long tail part

Deep (Intrinsic) Back: Superficial Layer

Splenius cervicis (neck attachment) Splenius capitis (attach to head) •'Bandages' that cover and hold deep neck mm. in position •Laterally flex neck, rotate head, extend head and neck Splenius Capitis Action: -Bilaterally: extends head and neck -Unilateral: bends and rotates ipsilaterally Innervation: Dorsal rami of mid cervical Splenius Cervicis Action: -Bilaterally: extends head and neck -Unilateral: laterally flex and rotate neck Innervation: Dorsal rami of lower cervical Cervicis is beneath capitis (think cap, attachment is on the skull) Superficial Laterally flex neck, contract both = extension of head and neck Splenius means bandage

In which space would you collect cerebrospinal fluid (CSF) during a lumbar puncture procedure?

Subarachnoid space

To perform a lumbar puncture, the needle passes through what layers in order from superficial to deep?

Supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space, dura mater, arachnoid mater

The body of the vertebrae is _______ and the spinous process is _________

The body of the vertebrae is anterior and the spinous process is posterior (what you can feel rubbing down your back)

4 normal adult curvatures of the spine

Thoracic & Sacral kyphoses -concave anteriorly Cervical and lumber lordoses -Concave posteriorly Primary (2X) curvatures develop during fetal period (thoracic and sacral) -Known as kyphosis: anterior concavity Secondary curvatures (2X) result from extention from fetal position (cervical and lumbar lordoses) -Posterior concave

A 44-year-old female presents in the clinic with weakness in adduction and extension of the upper limb. She underwent reconstructive breast surgery one month earlier. Which nerve was most likely damaged during the procedure?

Thoracodorsal

Deep (Intrinsic) Back: Deep Layer Transversospinalis Group

Transversospinalis Semispinalis (capitis and cervicis) Multifidus Rotatores •Major group (with three small parts: SMR) •Stabilization, extension, rotation Found in gutter between spinous and transverse processes *Lab likes to test you between semispinalis(contract left, move right?) and splenius muscles. Splenius is more superficial (splenius means bandaid)!

Joints of Vertebral Bodies: Intervertebral (IV) Discs (2 types)

Two types of IV disks Annulus Fibrosus: -Fibrocartilaginous ring -Thin posteriorly, thick anteriorly -Unites adjacent vertebrae •Nucleus pulposus -More cartilage and semifluid -Provides flexibility of disc -Shock absorption

Floor of subocciptal trraingle

Vertbral artery Floor: Posterior atlanto occipital membrane: Vertebral artery goes through it

Part: (Cervical, thoracic, lumbar) Body: Vertebral Foramen Transverse Process Articular Process Spinous Process Appearance Function:

Vertebral Foramen grows around spinal cord, makes a column

Spinal accessory (CN XI)

Which nerve innervates the muscle highlighted in the image?

Injury to Supporting Vertebral Structures: Whiplash Injury

Whiplash injury hyperextension injury damages ant longitudinal lig Torn anterior longitudinal ligament HYPEREXTENSION = ALL Hyperflexion, think everything else

A neuron with a cell body in the dorsal root ganglia could convey what type of fibers? a.Motor to the deep back muscles b.Motor to the pectoralis major muscle c.Sensory from skin overlying the trapezius d.Sympathetic preganglionics to the suprarenal medulla

c.Sensory from skin overlying the trapezius Remember: Dorsal (posterior side) root = SENSORY ONLY SAD = Sensory, Afferent, Dorsal

two enlargements of the spinal cord

cervical enlargement (serves upper limb) and lumbar enlargement (serves lower limb)

Spinal Segments

•Pairs of spinal cord nerves •Exiting the canal -C1-7: superior to corresponding vertebra (exit above corresponding vertebrae) -C8 : between C7 and T1 *but only seven cervical vertebrae -T1-L5: inferior to corresponding vertebra *Nerves now exit BENEATH corresponding vertebrae -S1-S4: inferior to corresponding vertebra -S5, Co1: through sacral hiatus *In the image!!!! Lumbar only has 5 pairs of nerves, not 12!!!!!!!

Vasculature of Vertebral Column (Arteries (Aa.))

•Periosteal and equatorial branches •Vertebral canal branches Not as worried about this: •Branches from -Vertebral aa., ascending cervical aa. -Segmental aa. •posterior intercostal aa. •subcostal aa. •lumbar aa. -Iliolumbar aa., lateral and median sacral aa.

Injury to Supporting Vertebral Structures: Herniated IV disc

•Posterolateral protrusion of nucleus pulposus •can be caused by traumatic or chronic injury (happens over time) •Commonly at L4-L5 or L5-S1 (becuase its supporting more of the weight) Herniated disc affects spinal n. at inferior level *Image: Axial view, spinous tail is posterior, top is anterior Anterior has much stronger ligament Posterior longitiudnal ligament is a lot weaker, so compression ususlly happens posto-laterally

Vertebrae Functions

•Protects spinal cord and nerves •Supports weight of body •Provides rigid and flexible axis •Facilitates posture and locomotion *Larger in size from superior to inferior *Thoracic: where the ribs articulate

Components of the Back

•Skin and subcutaneous tissue •Muscles: superficial that move upper limb, deep that move/stabalize spine •Vertebral column (Vertebrae and connective tissue) and spinal cord •Ribs (posterior portions) •Segmental vessels and nerves

Contents of Vertebral Canal

•Spinal cord •Spinal nerve rootlets/roots •Spinal meninges, CSF (and spaces, might contain fat) •Neurovascular structures anterior is the front (with all the vessles), posterior is to the back in the image Ligamentum Flavum very posterior

Great anterior segmental medullary a. (of Adamkiewicz)

•Supplies lower cord and reinforces anterior spinal a.

Lumbar Puncture: Withdrawal of CSF from:

•Withdrawal of CSF from lumbar cistern (portion of dural sac, expansion of subarachnoid space) •L3-4, L4-L5 to avoid cord (we need to know where the cord ends, which is around L1 or L2) Equina: Nerves below the cord Going into subaracnoid space *epidural anesthesia Anesthetic injected via lumbar puncture method, sacral hiatus, or sacral foramina